Micro-RNA-208a,-208b, and-499 as Biomarkers for Myocardial Damage after Cardiac Surgery in Children

Objectives: To test the hypothesis that cardiac-enriched micro-RNAs can serve as accurate biomarkers that reflect myocardial injury and to predict the postoperative course following pediatric cardiac surgery. Micro-RNAs have emerged as plasma biomarkers for many pathologic states. We aimed to quantify preoperative and postoperative plasma levels of cardiac-enriched micro-RNA-208a,-208b, and-499 in children undergoing cardiac surgery and to evaluate correlations between their levels, the extent of myocardial damage, and the postoperative clinical course. Design: PICU. Patients: Thirty pediatric patients that underwent open heart surgery for the correction of congenital heart defects between January 2012 to July 2013. Interventions: None. Measurements and Main Results: At 12 hours post surgery, the plasma levels of the micro-RNAs increased by 300-to 4,000-fold. At 24 hours, their levels decreased but remained significantly higher than before surgery. Micro-RNA levels were associated with troponin levels, longer cardiopulmonary bypass and aortic crossclamp times, maximal postoperative aspartate aminotransferase levels, and delayed hospital discharge. Conclusions: Circulating micro-RNA-208a,-208b, and-499 are detectable in the plasma of children undergoing cardiac surgery and may serve as novel biomarkers for monitoring and forecasting postoperative myocardial injury and recovery.